Rotary pump and fluid motor and sealing means therefor



June 21, 1966 K. EICKMANN 3,256,831

ROTARY PUMP AND FLUID MOTOR AND SEALING MEANS THEREFOR Filed Sept. 6, 1962 2 Sheets-Sheet 1 INVENTOR @rl LM Q June 21, 1966 K. EICKMANN 3,256,831

ROTARY PUMP AND FLUID MOTOR AND SEALING MEANS THEREFOR Filed Sept. 6, 1962 2 Sheets-Sheet 2 INVENTOR a.rl B h-44 BY 7M4! x 5%,

ATTORNEY United States Patent 3,256,831 ROTARY PUMP AND FLUID MOTOR AND SEALHNG MEANS THEREFOR Karl Eickrnann, 2420 Isshiki, Hayama-machi, Miuragun, Kanagawa-lren, Japan Filed Sept. 6, 1962, Ser. No. 221,909 Claims priority, application Japan, Sept. 11, 1959, 34/29,238; Germany, Sept. 8, 1961, E 21,640 18 Claims. (Cl. 103-136) The present application is a continuation-impart application of my copending application Serial No. 55,265, now abandonded.

The present invention relates to a rotary pump or fluid motor and more specifically to sealing means therefor. R-oary pumps or fluid motors usually comprise a housing defining an interior space and having at least one annular end face extending transversely to the axis of the annular housing, rotor means'turnably about a turning axis parallel to said axis Clf the housing and having a part located in the interior space of the housing and being formed with a plurality of angularly spaced radially inwardly extending slots. The rotor means may include at least one cover means having an annular face extending transversely to said turning axis and facing the annular end face of the housing defining a clearance space therewith and vane means reciprocably received in the slots and slidably engaging the inner surface of the housingso as to divide the interior space of the housing in "a plurality of fluid receiving intervane spaces or working chambers. During operation of the machine the working chambers successively pass through a pressure zone and a suction Zone. In machines of this type the axial pressure produced in the working chambers by the pressure fluid therein may partly or completely becompensated by pressure balancing means as for instance set forth in the co-tpending application Serial No. 55,265 and the sealing means according to the present invention which are located in the annular clearance space between the end face of the housing and the annular face of the cover means are especially useful in machines in which such pressure balancing means are provided.

It is an object of the present invention to provide in machines of the type mentioned above sealing means located in the annular clearance space between the end face or end faces of the housing and the annular faces of the cover means facing these end faces and which are constructed in such a manner to improve the sealing of said clearance space so as to prevent escape of pressure fluid therethrough and to reduce at the same time the friction'between the sealing elements and the faces engaged thereby so that the overall efficiency of the machine is improved and its useful life extended. 1

When for instance in machines of the type as set forth in the co-ipending application 55,265 the cover means are pressed against the end faces of the housing, it may happen that, especially in the region of the working chambers which pass through the suction zone or the zone of low pressure, there will be produced between the end faces of'the housing and the facing annular faces of the cover means such a great pressure that the efliciency of the machine is greatly reduced, whereas on the other hand in the compression Zone or zone of high pressure the cover means are pressed away from the end faces of the housing so that considerable leakage losses will occur. Due to the difference of pressure acting on the various portions of the cover means during operation of the machine, the annular faces of the cover means facing the end faces of the housing may be inclined relative to said end faces at a minute angle so that the faces of the cover means facing the end faces of the housing are not exactly parallel to the latter any longer.

It is a further object of the present invention to provide for an arrangement in which said small inclination will have no detrimental effect on the efficiency of the machine or the leaking losses.

Sealing rings between the annular end faces of the housing and the facing annular faces of cover means are known in the art, however experience has shown that such known sealing rings are not sufiioient to provide a proper seal, especially when the machine is operated at high pressure. The known sealing rings in such machines are subjected to relatively great deformations and, on the other hand, when such sealing rings are pressed over the total area of the opposite faces thereof between the end faces of the housing and the facing annular faces of the cover means, the resulting extremely high engaging pressure will lead to very great friction andaccordingly great efficiency losses.

It is yet an additional object of the present invention to avoid these difficulties and disadvantages of sealing rings known in the art.

With these objects in view, the .present invention includes in a rotary pump or fluid motor an annular housing defining an interior space and having at least one annular end face extending transversely to the axis of the annular housing, and a rotatable means is arranged rotatably about an axis parallel to the axis of the housing and at least partly in the interior space thereof and having an annular face extending transversely to the axis of the rotatable means, facing the annular end face of the housing, and defining a clearance space therewith, communicating 'with the interior space. A sealing ring is arranged within the annular clearance space and having an inner annular face facing the annular end face of the annular housing and being located closely adjacent the same over a predetermined area and an outer annular face facing the annular face of the rotatable means spaced therefrom over at least part of its surface so as to form a free annular space between at least part of the outer annular face of the sealing ring and the annular face of the rotatable means. Furthermore, sealing means are arranged within the free annular space so as toseal from the outer atmosphere at least a portion of the annular space which is bounded by a portion of said outer annular face of said sealing ring which has a smaller area than the predetermined area of said inner annular face. Passage means are also provided for conveying pressure fluid into said interior space of said housing and said portion of said annular space between said rotatable means and said sealing ring which is sealed from the atmosphere by the sealing means.

During operation of the machine pressure fluid at very high pressure will penetrate into the clearance space and thereby also into the gap between the end face of the housing and the annular inner face of the sealing ring. Since this last mentioned gap is extremely small and communicates at the outer periphery with the atmosphere, the pressure of the pressure fluid in the gap will gradually decrease from the radially inner edge of the sealing ring a to the radially outer edge thereof. On the other hand, the fluid pressure acting on the forementioned portion of the axially outer annular face of the sealing ring is substantially constant over the width of this face.

By properly dimensioning the sealing ring and by properly locating the sealing means on the sealing ring, it is possible to press the axially inner face of the sealing ring against the end face of the housing with such a pressure that, on the one hand, leakage losses are substantially avoided, whereas, on the other hand, excessive friction between sealing rings and end faces of said housing are avoided, even if the machine is operated at extremely high pressure.

The sealing ring is preferably made from metal and the sealing means are preferably in the form of a ring made from plastic material and arranged in an annular groove of the sealing ring.

The construction according to the present invention may also include a supporting ring arranged in the space between the end face of the housing and the facing end face of the cover means adjacent to the sealing ring, arranged thereto and cooperating therewith in such a manner that the pressure fluid in the interior of the housing presses the sealing ring and the supporting ring in opposite directions so that the sealing ring is pressed against the end face of the housing and the supporting ring against the annular face of the cover means facing the end face of the housing.

According to an another feature of the present invention, the sealing ring may also be formed in the inner annular face thereof with a plurality of cavities.

In this construction pressure fluid is also fed through passage means into the cavities formed in the sealing ring. In a preferred form of this construction the passage means for feeding pressure fluid into the cavities are arranged in such a manner so as to respectively connect the cavities with working chambers which are located in any instance substantially diametrically opposite to the respective cavities.

The novel features which are considered as characteristicfor the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a partial axial section through a machin according to the present invention;

FIG. 2 is a section along line 22 of FIG. 1;

FIG. 3 is a partial cross section through a detail of FIG. 1 encompassed in the circle marked 3 and drawn to a larger scale;

FIG. 4 is a partial cross section similar to FIG. 1 and showing a different embodiment according to the present invention and including a supporting ring;

FIG. 5 is a partial cross section similar to FIG. 1, drawn to an enlarged scale and showing a further embodiment;

FIG. 6 is a partial end view of the sealing ring of the embodiment shown in FIG. 5; and

FIG. 7 is a partial cross section similar to FIG. 4 and showing a further modification according to the present invention.

Referring now to the drawings and especially to FIGS. 1-3 of the same, it will be seen that the machine of the present invention includes an annular housing part 28 defining an interior space or cavity and having a pair of end faces. The machine includes further rotatable means, rotatable about an axis parallel to the axis of the housing and at least partly in the interior space and having annular end faces extending transversely to the axis of the rotatable means and facing the annular end faces of the housing part 28 and defining an annular clearing gap 54 therewith. More specifically, the rotatable means shown in FIGS. 1-3 include a hollow rotary shaft 17 having an 4 extended portion 18 which may serve as drive shaft when the machine is used as pump and, when the machine is used as fluid motor, as the driven shaft. A flange 19 extending normal to the shaft axis is integrally connected to the shaft 17 in the region where the extension 18 is joined to the shaft. The rotatable means of the embodiment shown of FIGS. 13 include further a central rotor portion 22, rotor side walls 21 and 23 abutting respectively against opposite ends of the central rotor portion 22, and cover portions or cover means and 24 respectively abutting against the outer ends of the side wall portions 21 and 23. The left cover 24, as viewed in FIG. 1 is formed with a central cavity in which a piston 25 is slidably arranged for a purpose which will be described later on. Abutting against the left face of piston 35, as viewed in FIG. 1, is a flange ring 26, which is slidably arranged on the hollow shaft 17. The slidable flange ring 26 is connected by a plurality of screw bolts 27 respectively passing through aligned bores of the members 26, 24, 23, 22, 21, 20 and 19 so that these members are connected to each other and also connected to the hollow shaft 17 for rotation therewith. The annular housing 28 is turnably mounted in a support 29 which may be stationary or Which may be also turnably mounted 7 on the shaft 17, 18 prevent axial shifting of the latter as well as the elements mounted thereon for simultaneous rotation with respect to the ball bearings 15 and 16. The rotor 22 and the side wall portions 21 and 23 are formed respectively with a plurality of radially extending slots 31, 32 and 33 and the slots in the three mentioned elements are respectively aligned with each other. Wings or vanes 34 are respectively mounted in these slots reof the machine.

ciprocable in radial direction and each of the wings 34 has at the outer end portions thereof radial extensions 35 and 36 which slide in the slots 31 and 32 of the side walls 21 and 23. The radially outer edge portions of the wings 34 between the extensions 35 and 36 abut, as clearly shown in FIG. 2 against the inner surface of the annular housing 28, whereas the radial extensions 35 and 36 slide with the inner edges 37 and 38 with very small clearance against the annular end faces of the annular housing 28.

A control member 10 is mounted in the interior of the hollow shaft 17, 18, and this control member is connected to the machine frame in a known manner, not illustrated in the drawing, preferably shiftable in axial direction while being prevented from turning about the axis of the shaft 17, 18. The control member 10 is formed in its interior with a pair of passages 11 and 12, best shown in FIG. 3, which serve to feed pressure fluid into and out The hollow shaft 17 and the rotor 22 is further formed with a plurality of radially extending slots 39 therethrough which are respectively arranged between the slots 32 in which the wings 34 are mounted.

During rotation of the machine, the working chambers 40 respectively formed between successive wings 34, the outer peripheral surface of the rotor 22 and the inner peripheral surface of the annular housing 28 are thus alternatively connected by means of the slots 39 and the windows 13 and 14 formed in the control member 10 to the inlet and outlet passages 11 and 12 of the pressure fluid. The working chambers 40 pass during each revolution of the rotor 22, respectively the rotor assembly 17-27 through a suction zone and a pressure zone. One of the zones is indicated in FIG. 2 with x, whereas the other zone is indicated in FIG. 2 as y. Depending on the rotation of the machine and depending on whether the machine is used as pump or as fluid motor, one of the zones will be the suction zone and the other pressure zone.

Assuming a rotational direction as indicated by the arrow a in FIG. 2, and assuming further that the machine is used as pump or compressor, then the zone marked x in FIG. 2 would be the suction zone and the zone marked y the pressure zone. In such an arrangement the pressure fluid will be sucked in the region of the suction zone x through the passage 11, the window 13 and the radial slots 39 into working chambers 40 shown at the left side of FIG. 2, the volume of which increase during rotation of the machine, whereas in the region of the pressure zone y the pressure fluid will be pressed out of the working chambers 40 shown at the right side of FIG. 2 through the radial slot 39, the window 14, into the passage 12.

If at the same time pressure fluid is fed into the pressure balancing cylinder 30 in a manner as more clearly described in the co-pending application 55,265, the cover member 24 is pressed toward the right, as viewed in FIG. 1, whereas the slidable flange ring 26 is pushed through the balancing piston 25 towards the left to exert thereby through the bolts 27 a pressure towards the left, as viewed in FIG. 1, on the flange ring 19 and the cover member 20 abutting thereagainst. The cover members 20 and 24 are thereby pressed inwardly against the opposite end faces of the annular housing 28, whereby the outward pressure exerted on the cover members 20 and 24 by the pressure fluid in the working chambers 40 is counteracted so that a small clearance space or gap 41 will remain between the annular end faces of the annular housing 28 and the facing annular faces of the cover members 20 and 24.

Sealing rings 42, are provided to seal each clearance gap to prevent escape of pressure fluid through the same. One of the sealing rings is shown in cross section and at an enlarged scale in FIG. 3. The sealing ring 42 slides with its inner annular face 43 of predetermined relative large area on the annular end face of the annular housing 28, whereas the outer side of the sealing ring is provided with oflset annular face portions 44 and 45 which are connected with each other by a cylindrical face 46. The sealing rings 42 of the embodiment shown in FIGS. 1-3 are respectively arranged in annular grooves 47 respectively formed in the cover members 2%) and 24. Each of the grooves 47 has a cross sectional outline similar to that of the sealing ring 42 arranged therein, but a cross sectional area larger than the cross sectional area of the respective sealing ring so that a free annular space 48, 51, 52, and 53 is formed between the groove surface and the corresponding surfaces of the sealing ring as shown in FIG. 3. The portion 48 of the annular free space communicates through a gap 49 with the clearance space or gap 41, whereas the portion 53 of the free annular space directly communicates with the outer portion 54 of the clearance space between the respective cover member and the end face of the annular housing. Addi tional sealing means 50, preferably in the form of a ring set into a groove of the sealing ring 42, seals a portion of the aforementioned free annular space from the outer atmosphere, which portion is substantially bounded by the face portion 44 which has a substantially smaller area than the inner annular face portion 43 of the sealing ring 42.

The free space between sealing ring 42 and the corresponding groove surfaces will assure that during different heat expansion of the various members or during the deformation of the sealing ring 42 under the influence of the great pressure acting thereon, wedging of these members against each other is positively avoided.- The portion 48 of the free annular space may also be connected through a plurality of bores 57 with the radial slots 31 or 32, whereas the portion 53 of the free space may be connected through additional bores 58 to the outer atmosphere. A pin 59 fitted with a press fit into a bore of the cover member or otherwise fixedly connected thereto and extending with a slide fit into a bore a 6 formed in the sealing ring 44. may also be provided to prevent rotation of the sealing ring 42 with respect to the respective cover member.

The sealing rings 42 are preferably made from metal, whereas the sealing means or the additional sealing rings 50 are preferably made from plastic material. If desired, an additional preferably plastic sealing ring may also be provided in the gap 49 so as to seal the gap 48 against the gap 41. In this case the annular gap 48 is only connected to the slots 31 or 33 through the bores 57.

The described sealing arrangement willwork as follows:

Pressure fluid in the working chambers 40 will enter through the gap 41 into the small annular gap 55 between the inner annular face 43 of the sealing ring 42 and the annular end face of the annular housing 28. Since the outer end of the clearance space between the facing annular faces of housing and cover communicates with atmosphere, it is evident that the pressure in the gap 55 will gradually decrease in radially outward direction so that the median pressure per area unit in the gap 55 will be normally smaller than the pressure per area unit in the portion 48 of the annular free space which is sealed off from the outer atmosphere by the additional sealing means 50.

The greater the radial dimension of the inner annular face 43 of the sealing ring or the radial dimension of the gap 51, the greater will be the pressure which acts on the face 43 to press the sealing ring 42 in axially outward direction. Therefore, itis possible to dimension the area of the face 43 in such a manner that the pressure fields forming on the one hand in the [gap 55 and on the other hand in the portion 48 of the annular free space which is sealed off from the outer atmosphere and which is subjected to the full pressure of the pressure fluid will compensate each other completely or nearly completely. In actual practice it is preferred to dimension the annular face 44 of the sealing ring and to arrange the sealing means 50 in such a manner that the force produced by the fluid pressure in the gap portion 48 is from 3% to to 30% greater than the force in opposite direction produced by the decreasing fluid pressure in the gap 55. In this way it is possible to obtain a nearly perfect seal between the annular housing and the cover members 20 and 24, while simultaneously holding the friction to a minimum.

If the machine is operated with very high pressure, it is preferred to grind the annular faces of the cover members 20 and 24 which are directed towards the end faces of the annular housing not parallel to the latter, but especially radially outwardly of the sealing rings 42, at a small angle corresponding approximately to half of the deformation angle included between the cover members 20 and 24 at such great pressures. The wedge shaped outwardly increasing gap 54 is indicated in FIG. 1 and it should be mentioned that this gap, as well as the gap 41, is shown in FIG. 1 to an exaggerated size. Actually the total deformation of the cover members 20 and 24 will be within a few hundreds or thousands of a millimeter, however, even this small deformation has at-the high pressures at which the machine is operated a considerable effect on the efficiency of the machine.

Another modification is shown in FIG. 4 in partial cross section'and it is to be understood that the arrangement shown in FIG. 4 is, except for the details pointed out below, similar to the arrangement as shown in FIG. 1. The embodiment shown in FIG. 4 differs from the arrangement shown in FIGS. 13 in that an additional supporting ring is provided in combination with a sealing ring 142 in the clearance space between the annular end face of the annular housing 128 and the facing annular face of the respective cover member 120. The

sealing ring 142 abuts with its inner annular face against the end face of the annular housing 128, where-as the supporting ring 160 abuts against the corresponding face of the cover member 120. Furthermore, the sealing ring 142 and the supporting ring 160 are arranged in such a manner that they close radially outwardly the slot 131 guiding extensions of the wings 134. The sealing ring 142 is of similar construction as the sealing ring 42 shown in the FIGS. 1-3, that is the sealing ring 142 has on its axial outer side a pair of offset annular face portions 144 and 145 which are connected by a cylindrical surface which is provided with an annular groove in which a sealing means, or an elastic sealing ring 150 is arranged, which abuts with its outer peripheral face against the corresponding cylindrical face of the supporting ring 160 to positively seal the free annular space 148 formed between the annular face portion 144 of the sealing ring and the corresponding face portion-of the supporting ring 160 from the outer atmosphere. The area of the face portion 144 of the sealing ring 142 is again, as in the embodiment shown in FIGS. 1-3, considerably smaller than the area of the inner annular face 143 of the sealing ring. Cavities 161 may be formed in the sealing ring 14-2 extending into the same from the inner annular face 143. These cavities 161 may be angularly spaced about the circumference of the ring and they may be also connected by an annular groove. They may be also connected to a source of pressure fluid.

An elastic sealing ring 162 may also be provided to seal any small gap 163 between the supporting ring 160 and the annular face of the cover member 120, to prevent escape of pressure fluid from the slot 131. between the cover member and supporting ring.

The pressure fluid in the slots 131 enters into the gap or annular free space 148 between supporting ring and sealing ring so that the sealing ring 142 is pressed against the end face of the annular housing 128, whereas the supporting ring 162 is pressed against the cover member 120. The chambers formed in the guide slots 131 radially outwardly of the wings 134 are preferably connected, for instance through the gap at the ends of the wings, with the chambers of the slots 131 formed at the radially inner side of the wings 134 and thereby to the pressure fluid conduit of the machine.

The embodiment shown in FIG. 4 permits the use of especially strong sealing rings 142. In this embodiment it is also possible to form the cover members substantially as plane discs which results in a construction of unobvious simplicity. On the other hand, it is also possible to form the cover members with shoulders or flanges projecting toward the end faces of the annular housing, or the slots 133 may be closed radially outwardly by an additional closure ring located inwardly of sealing ring 142 and supporting ring 160, which ring would have to be provided with bores similar to the bores 57 shown in the embodiment of FIGS. 1-3. Sealing ring 142 and supporting ring 160 may also be connected in a manner not shown in FIG. 4, for instance by pins, to prevent rotation of these two members relative to each other if such is desired.

Transmission means, such as for instance gears, friction wheels, or levers, etc., may also be provided between friction ring 142 or supporting ring 160, on the one hand, and the annular housing 128 and cover 128, on the other hand, in such a manner to transmit the relative movement between the annular housing 128 and the cover member 120 to the friction ring 142 and supporting ring 160 so that these two ring members will move relative to housing and cover member with a speed which is smaller than the relative speed between the housing 128 and the cover member 120. Such an arrangement provides for an additional considerable reduction of friction losses since the relative speed between the slide faces of housing 128 and sealing ring 142, on the one hand, and the relative speed between supporting ring 164 and the cover member 122 on the other hand, is considerably reduced. In such an arrangement it is preferred to omit the plastic sealing ring 162. During such a positive control of the relative speeds and therewith reduction of the relative speeds between cover member and supporting ring 16b, and between sealing ring 142 and housing 128, the reduction of the relative speeds is practically linear. The linear reduction of the relative speeds will result in reduction of the friction loss according to the square function so that the sum of the friction losses between the above-mentioned faces will be smaller than would be the friction loss between the engaging faces of the annular housing 128 and the sealing ring 142, if the latter would be fixedly connected to the supporting ring 169 and the cover member 120. If for instance the relative speeds between the forementioned members is reduced to the half, it will result in a reduction of the friction losses to a quarter so that the sum of the friction losses will be about 50% smaller than the friction losses resulting from an arrangement in which sealing ring 142, supporting ring 161 and the side wall member 120 would be connected to each other for simultaneous rotation at equal rotational speeds.

It is also possible to provide a plurality of sealing rings 142 and supporting rings 16%) aligned in axial direction between the housing 123 and the cover member 120 and to connect these members for positive control of the relative speeds to each other. In this way it is possible to obtain a further reduction of the relative speeds and therewith a corresponding considerable reduction of the friction losses.

Various constructions are known for controlling the relative speed between engaging discs or similar members which rotate with respect to each other. Such known transmission means will result in the desired effect according to the present invention when they are arranged in such a manner that the sealing ring and the supporting ringbetween housing 128 and cover member 120 will obta1n relative speeds with respect to housing and cover member which are smaller than the relative speed between housing 128 and cover member 120. A specific arrangement for such transmission means will be described later on.

FIGS. 5 and 6 illustrate another embodiment according to the present invention. and it is to be understood that the embodiment shown in FIGS. 5 and 6 is similar to the embodiment shown in FIGS. l-3 and diifers therefrom only by details as described below. The sealing r ng 242 of a cross section very similar to the sealing ring 42 shown in FIG. 1 is arranged, as in the first embodiment, in an annular groove of corresponding cross section formed in the cover member 220. The sealing ring 242 is formed with a plurality of arcuate cavities 261 which extend from the inner annular face 243 of the sealing ring into the sealing ring. Pressure fluid may be fed into the cavities 261 to provide thereby pressure fields to properly balance the sealing ring 242.

The plurality of cavities 261 are separated from each other and are distributed along the inner annular face 243 of the sealing ring in the manner as partly shown in FIG. 6. Preferably the total number of cavities 261 is equal to or a multiple of the number of working chambers 40 of the machine. In the preferred embodia ment, partly shown in FIG. 5, the cavities 261 are respectively connected with diametrically opposite arranged working chambers 246b, that is, with working chambers which are at any given instant subjected to a pressure diflerent from the pressure to which the working chambers 240a adjacent to the respective cavities 261 is subjected. In other words, when during the revolution of the machine the working chamber next to one of the cavities 261, for instance the working chamber 240a, is located in the suction Zone of the machine, the cavity 261 is connected to a working chamber 249]) which is located at this 1nstant in the pressure zone of the machine. The connection between each of the cavities 261 with the working chamber located diametrically opposite thereto is provided by the bore 264 in the sealing ring 242 and the bore 265 which passes through the cover 220 and the rotor disc 221 which is fixedly connected thereto. Each of the bores 265 communicates with the end thereof opposite to the respective cavity with a corresponding working chamber. The bores 264 and 265 are respectively connected to each other by sleeves 266, which are sealed on the side of the sealing ring 242 and on the side of the cover member 220 by elastic seals 267 to prevent comrnunication between the bores and the space 248, 249. Of course, the individual bores 265 which connect the respective cavities 261 with the working chambers diametrically opposite thereto must be kept separated from each other so as not to provide a connection between the working chambers. 'The wings 234 only partly shown in FIG. 5, may be constructed in a similar manner as described in connection with FIG. 1.

The results obtained from the arrangement shown in FIG. will be clear from the above description of the arrangement. If, for instance, the working chamber 240a shown in FIG. 5 is subjected to high pressure, the cavity 261 adjacent to the working chamber 248 will be provided with pressure fluid from the diametrically opposite working chamber 24017 which is at this instance under low pressure. Since the annular free space 248 behind the sealing ring 242 is sealed off from the outer atmosphere by the sealing means 250 and communicates in the manner described before with the working chamber 240a at high pressure, and since the cavity 261 communicates with a working chamber 240!) at low pressure, the inner annular face 243 of the sealing ring 242 will be pressed with relatively great pressure against the corresponding end face of the housing 228 so that corresponding to the high pressure in the adjacent working chamber 240a the pressure on the sealing ring at the portion thereof adjacent to the working chamber 240a is likewise increased so that escape of pressure fluid from the working chamber 240a is positively avoided. On the other hand, if the working chamber 2400 is at low pressure, the diametrically opposite working chamber 24% will be at high pressure so that pressure fluid under high pressure will be directed in the cavity 261 adjacent the chamber 240a, whereby this portion of the sealing ring. 242 will be pressed with lower pressure against the corresponding end face of the housing 228 so that the friction between this portion of the sealing ring 242 and the corresponding end face of the housing 228 is reduced.

The cavities 261 will also provide balancing compartments to compensate completely or partly for the pressure difference acting from opposite sides on the sealing ring 242. The pressure difference results, as explained above from the fact that pressure medium enters from the various working chambers with different pressures into the clearing space 243 between the opposite faces of the housing and the sealing rings 242 whereby the sealing ring 242 is acted upon with different resulting pressures from the sealing gap between housing and sealing ring and from the annular space 248 on the opposite side of the sealing ring.

It is understood that the connection between the individual cavities 261 and the diametrically opposite working chambers 24% may also .be made in a manner different from the only schematically illustrated arrangement shown in FIG. 5.

FIG. 7 illustrates an arrangement as mentioned above for controlling the relative speeds between the annular housing, sealing and supporting rings, and the cover rnember. 1n the arrangement shown in FIG. 7, a shaft 1725 is pressed into a bore of the supporting ring 160 or otherwise fixedly connected thereto projecting with an end portion thereof in radial direction outwardly of the supporting ring 160. Turnably mounted on the outer end of the shaft 1725 is a conical gear 1724 which is held on the shaft against axial displacement by the shoulder portion 1726 on the free end of the shaft. The conical gear 1724 meshes with diametrical opposite portions thereof respectively with corresponding gear rings 1727 and 1728 respectively fixed or integrally made with the housing 128 and the cover member 120. When the rotor of the machine and therewith the cover member rotates relative to the annular housing 128 at a given speed, the gear 1724 will be rotated and the shaft 1725 as well as the supporting ring connected thereto will be moved about the axis of the rotor with a speed approximately half the relative speed between cover member 120 and housing 128. The sealing ring 142 may in this construction 'be connected to the. supporting ring 160 for a simultaneous rotation;

It will be understood that each of the elements described above, and especially the sealing ring arrangement according to the present invention may also find a useful application in other types of machines than in rotary pumps or fluid motors described above. Especially the sealing ring arrangement with or without an additional support ring may be used also on rotary pumps or fluid motors which are not provided with pressure balancing means 30, 25 and the specific arrangement of the other machine elements cooperating therewith as described in connection with FIG. 1. The specific sealing arrangement according to the present invention may also be used in machines of this type in which the various elements of the rotatable means are connected not by bolts 27 as shown in FIG. 1 but by any different known connecting means.

Furthermore, the sealing arrangement of the present invention may also be used not only in a seal between the annular housing and the cover members, but the sealing arrangement may also be used between other parts of similar machines which are moved relative to, each other.

While the invention has been illustrated and described as embodied in a rotary pump or fluid motor, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. I

Thus, the sealing arrangement according to the present invention may also be used in connection with other machines such as for instance combustion engines, gas

motors, steam engines and similar fluid operated machines.

I claim:

1. In a rotary pump or motor, in combination, a housing having an annular housing part having an' axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and defining an open space with at least part of said annular end face; at least one sealing ring located in a part of said space and having on one side a sealing face substantially parallel to said annular end face and being in sealing engagement therewith and having on the other side a pressure face; sealing means provided between said sealing ring and said cover means for sealing an inner portion of said space containing said pressure face in radially outward direction; and passage means for supplying pressure fluid from said interior cavity into said inner portion of said space so that said sealing ring is pressed into sealing engagement with said end face 'by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

2. In a rotary pump or motor,-in combination, a housing having an annular housing part having an axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending transversely to said axis and confronting said annular end face of said housing part and defining with the same an annular open clearance gap communicating with said interior cavity, said annular face of said cover means being formed with a recess open toward said clearance gap and said annular end face; at least one rigid sealing ring located in a part of said recess and having on one side a sealing face substantially parallel to said annular end face and being in sealing engagement therewith and having on the other side a pressure face; sealing means provided between said sealing ring and said cover means for sealing an inner portion of said recess containing said pressure face in radially outwarddirection from said clearance gap; and passage means for supplying pressure fluid from said interior cavity into said inner portion of said recess so that said sealing ring is pressed into sealing engagement with said end face by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

3. In a rotary pump or motor, in combination, a housing having an annular housing part having an'axis, an inner annular face surrounding a interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers including a chamber containing pressure fluid, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending transversely to said axis and confronting said annular end face of said housing part and defining with the same an annular clearance gap communicating with said interior cavity, said annular face of said cover means being formed with an annular groove coaxial with said rotor axis and being open toward said clearance gap and annular end face and having a bottom face spaced from said end face of said cover means; a sealing ring located in said groove and having opposite transverse faces, one of said transverse faces being substantially parallel to said annular end face and in sealing engagement therewith, and the other of said faces being a pressure face confronting said bottom face spaced there from so as to form a free annular space; and passage means in said cover means extending from said chamber which contains pressure fluid to said free annular space whereby said sealing ring is pressed into sealing engagement with said end face by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

4. In a rotary pump or motor, in combination, a housing having an annular housing part having an axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers including a chamber containing pressure fluid, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending-transversely to said axis and confronting said annular end face of said housing part and defining with the same an annular clearance gap communicating with said interior cavity, said annular face of said cover means being formed with an annular groove coaxial with said rotor axis and being open toward said clearance gap and annular end face and having a bottom face spaced from said end face of said cover means; a sealing ring located in said groove and having opposite transverse faces, one said transverse faces being substantially parallel to said annular end face and in sealing engagement therewith, and the other of said faces being a pressure face confronting said bottom face spaced therefrom so as to form a free annular space; sealing means provided between said sealing ring and said cover means for sealing a portion of said free annular space in radially outward direction from said clearance gap; and passage means in said cover means extending from said chamber which contains pressure fluid to said portion of said free annular space whereby said sealing ring is pressed into sealing engagement with said end face by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

5. In a rotary pump or motor, in combination, a housing having an annular housing part having an axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel. to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending transversely to said axis and confronting said annular end face of said housing part and defining with the same an annular open clearance gap communicating with said interior cavity, said annular face of said cover means being formed with a recess open toward said clearance gap and said annular end face; a rigid sealing ring and a rigid supporting ring located in said space and defining a ring space between each other, said sealing ring having on one side a sealing face substantially parallel to said annular end face and in sealing engagement therewith, and on the other side a pressure face spaced from said supporting ring, and said supporting ring having an annular end face in engagement with said cover means; a sealing means disposed between said sealing ring and said supporting ring in said ringvspace for sealing an inner portion of said ring space from said clearance gap in radial outward direction; and passage means for supplying pressure fluid from said interior cavity into said inner portion of said ring space so that said sealing ring is pressed into sealing engagement with saidend face by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

6. In a rotary pump or motor, in combination, a housing having an annular housing part having an axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely to the axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers including a chamber containing pressure fluid, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending transversely to said axis and confronting said annular end face of said housing part and defining with the same an annular clearance gap communicating with said interior cavity, said annular face of said cover means being formed with an annular groove parallel to said annular end face and in sealing engagement therewith, and the other of said faces being a pressure face confronting said bottom face spaced therefrom so as to form a free annular space, said pressure face having a smaller radial extension than said one transverse face and a smaller area; and passage means in said cover means extending from said chamber which contains pressure fluid to said free annular space whereby said sealing ring is pressed into sealing engagement with said end face by pressure fluid acting on said pressure face against the action of the pressure fluid on said annular end face.

7. In a rotary pump or motor, in combination, a housing having an annular housing part having an axis, an inner annular face surrounding an interior cavity, and at least one annular end face extending transversely tothe axis of said housing part; rotor means arranged at least partly in said interior cavity for turning movement about a rotor axis parallel to said axis, said rotor means including means for partitioning said interior cavity into a plurality of fluid receiving working chambers including a chamber containing pressure fluid, and at least one cover means having a portion extending outwardly beyond said inner annular face of said housing part and having an annular face extending transversely to said axis and confronting said annular end faceof said housing part and defining with the same an annular clearance gap communicating with said interior cavity, said annular face of said cover means being formed with an annular groove coaxial With said rotor axis and being open toward said clearance gap and annular end face and having a bottom face spaced from said end face of said cover means and a stepped outer-annular face; a sealing ring located in said groove and having a stepped outer annular face spaced from said stepped outer annular face, and opposite transverse faces, one of said transverse faces being substantially parallel to said annular end face and in sealing engagement therewith, and the other of said faces being a pressure face confronting said bottom face spaced therefrom so as to form a free annular space, said pressure face having a smaller radial extension than said one transverse face and a smaller area; a ring-shaped sealing means located between said stepped annular faces for sealing an inner portion of said free annular space containing said pressure face for sealing an inner portion of said free annular space containing said pressure face from communication with the atmosphere; and passage means in said cover means extending from said chamber which contains pressure fluid to said inner portion of said free annular space whereby said sealing ring is pressed into sealing engagement with said end face by pressure fluid acting on said pressure face against the action of the pres sure fluid on said annular end face.

8. A pump or motor as set forth in claim 7 and including passage means formed in said cover means and connecting a portion of said free annular space located outward of said sealing means with the atmosphere.

9. A pump or motor as set forth in claim 7 wherein said housing part and said cover means form an annular clearance gap radially outward of said groove and bounded by said end face and by a part of said annular face of said cover means which is slightly inclined to said end face so that the clearance increases outwardly.

10. A pump or motor as set forth in claim 1 and including means securing said sealing ring to said cover means to prevent rotation of said sealing ring relative to said cover means.

11. In a rotary pump or fluid motor, in combination, an annular housing defining an interior space and having at least one annular end face extending transversely to the axis of said annular housing; rotor means arranged at least in part in said interior space turnable about a turning axis substantially parallel to said axis of said housing and including at least one cover means having an annular face extending transversely to said turning y axis and facing said annular end face of said housing and defining an annular clearance space therewith communicating with said interior space; a sealing ring arranged within said annular clearance space and having an inner annular face facing said annular end face of said annular housing located closely adjacent the same over a predetermined area, and offset outer face portions substantially parallel to said inner annular face, one of which is radially outwardly located with respect to the other offset face portion and spaced closer to said inner annular face than said other of said offset face portions, and a cylindricalface extending between said offset face portions; a supporting ring located adjacent said sealing ring in said clearance space and having an axially outer annular face engaging said annular face of said cover means, and a pair of offset face portions facing said offset face portions of said sealing ring and spaced at least from said other of said offset face portions of the latter, and a cylindrical face extending between said offset face portions of saidsupporting ring and slidably engaging said cylindrical face of said sealing ring; annular sealing means in sealing engagement with said cylindrical faces of said sealing ring and said supporting ring so as to seal from the outer atmosphere afree annular space portion between said other offset face portion of said sealing ring and the facing offset portion of said supporting ring; and passage means for conveying pressure fluid into said interior space of said housing and said sealed-off portion of said annular free space between said sealing ring and said supporting ring so that pressure fluid entering into said portion of said annular free space will press said sealing ring and said supporting ring in opposite directions respectively against said annular end face of said housing and said annular face of said cover means.

12. In a rotary pump or fluid motor, in combination, an annular housing defining an interior space with pumping chambers or motor chambers therein and having at least one annular end face extending transversely to the axis of said annular housing; rotatable means arranged rotatably about an axis parallel to said axis of said housing and at least partly in said interior space and having an annular face extending transversely to the axis of said rotatable means and facing said annular end face of said housing and defining an annular clearance space therewith communicating with said interior space; a sealing ring arranged within said annular clearance space and having an inner annular face facing said annular end face of said annular housing located closely adjacent the same over a predetermined area and an outer annular face facing said annular face of said rotatable means spaced therefrom over at least part of its surface so as to form a free annular space between at least part of said outer annular face of said sealing ring and said annular face of said rotatable means, said sealing ring being formed with a plurality of cavities extending from said inner annular face inwardly into said sealing ring; sealing means arranged within said free annular space so as to seal from the atmosphere at least a portion of said annular space which is bounded by a portion of said outer annular face of said sealing ring which has a smaller area than said predetermined area of said inner annular face; and passage means for conveying pressure fluid into said interior space of said housing, said portion of said annular space between said rotatable means and said sealing ring and into said cavities of said sealing ring. I

13. In a rotary pump or fluid motor, in combination, an annular housing defining an interior space and having at least one annular end face extending transversely to the axis of said annular housing; rotor means arranged at least in part in said interior space turnable about a turning axis substantially parallel to said axis of said housing and including at least one cover means havingan annular face extending transversely to said turning axis and facing said annular end face of said housing and defining an annular clearance space therewith communicating with said interior space, said cover means being formed with an annular groove coaxial with said turning axis and extending from said annular face into said cover means, said groove having a bottom face spaced fromsaid annular face of said cover means; a sealing ring arranged within said annular groove and having an inner annular face facing said annular end face of said annular housing located closely adjacent the same over a predetermined area and an outer annular face facing said bottom face of said groove spaced therefrom over at least part of its surface so as to form a free annular space between at least a part of said outer annular face of said sealing ring and said annular face of said cover means; sealing means arranged within said free annular space so as to seal from the atmosphere at least a portion of said annular space which is bounded by a portion of said outer annular face of said sealing ring which has a smaller area than said predetermined ,area of said inner annular face; passage means for conveying pressure fluid into said interior space of said housing and said portion of said annular space between said cover means and said sealing ring; and transmission means operatively connected to said housing, said cover means and said sealingring for causing said sealing ring to rotate at slower speed relative to said end face of said housing than said cover means.

14. In arotary pump or fluid motor, in combination, an annular housing defining an interior space and having at least one annular end face extending transversely to the axis of said annular housing; rotor means arranged at least in part in said interior space turnable about a turning axis substantially parallel to said axis of said housing and including at least one cover means having an annular face extending transversely to said turning axis and facing said annular end face of said housing and defining an annular clearance space therewith comm-unicating with interior space; a sealing ring arranged with said annular clearance space and having an inner annular face facing said annular end face of said annular housing located closely adjacent the same over a predetermined area, and offset outer face portions substantially parallel to said inner annular face, one of which is radially outwardly located with respect to the other offset face portion and spaced closer to said inner annular face than said other of said offset face portions; a supporting ring located adjacent said sealing ring in said clearance space and having an axially outer annular face engaging said annular face of said cover means, and a pair of offset face portions facing said offset face portions of said sealing ring and spaced at least from said other of said offset face portions of the latter, and a cylindrical face extending between said oifset face portions of said supporting ring and slidably engaging said cylindrical face of said sealing ring; annular sealing means in seal-ing engagement with said cylindrical faces of said sealing ring and said supporting ring so as to seal from the outer atmosphere a free annular space portion between said other offset portion of said supporting ring; passage means for conveying pressure fluid into said interior space of said housing and said sealed-off portion of said annular free space between said sealing ring and said supporting ring so that pressure fluid entering into said portion of said annular free space will press said sealing ring and said supporting ring in opposite directions respectively against said annular end face of said housing and'said annular face of said cover means; and transmission means operatively connected to said housing, said cover means and said supporting ring for causing said supporting ring to rotate at slower speed relative to said end face of said housing than said cover means.

15. In a fluid handling device, in combination, a housing; a rotor means rotatably mounted in said housing; a rotary casing ring means having an axis spaced from the a is Of sa d rotor means; side Wall means'located at the ends of said rotor means and having radial portions extending in radial direction beyond said rotor means and being connected with said rotor means for rotation therewith; said rotary casing ring means having planar end faces and said side wall means having planar inner faces on said radial portions facing at least partially said end faces of said rotary casing ring means; said rotor means having substantially radial slots; vane means slidably disposed in said slots; said rotary casing ring means, said rotor means, and said side wall means forming together a fluid-containing working chamber, and said vane means dividing said working chamber into a plurality of separate intervane spaces periodically increasing and decreasing in volume during rotation of said rotor means; passage means including inlet means and outlet means for passing fluid to and from said intervane spaces; said side wall means being formed with at least one annular groove extending from one of said inner faces into one of said radially extending port-ions; and ring means located in said annular groove and defining a fluid-containing pres- I sure chamber in the same behind said ring means; said passage means including a high pressure passage and communication passage means establishing communication between said high pressure passage and said fluid-containing pressure chamber for maintaining therein fluid under pressure.

16. A device as set forth in claim 15 and including an interchanging device for alternatively connecting one or the other of said passage means with said fluid-containing pressure chamber depending on which of said passage means has higher pressure.

17. A device as set forth in claim 15 and including means for establishing communication between said fluidcontaining chamber and said radial slots, and with said high pressure passage.

18. In a fluid handling device, in combination, a housing, rotor means rotatably mounted in said housing; side wall means located at the ends of said rotor means having radial portions extending in radial direction beyond said rotor means and being connected with the same for rotation therewith, a casing ring means having an axis spaced from the axis of said rotor means and having planar end faces, said side wall means having planar inner faces on said radial portions facing at least partially said end faces of said casing ring means, said rotor means having radial slots, and said side wall means having radial References Cited by the Examiner UNITED STATES PATENTS 810,062 l/1906 Lind 91-134 1,001,162 8/1911 Parsons et al. 91121 2,098,652 11/1937 Buckbee 103-136 2,371,081 3/1945 Tucker et al 103136 2,386,873 10/1945 Mercier 277-188 2,654,325 10/1953 Minshall 103-126 2,778,598 1/1957 Bolling 277l88 2,962,314 11/1960 Rickard 277l88 3,011,803 12/1961 Buckner et a1 277l88 SAMUEL LEVINE, Primary Examiner.

JOSEPH H. BRANSON, JR., Examiner.

R. M. VARGO, Assistant Examiner. 

1. IN A ROTARY PUMP OR MOTOR, IN COMBINATION, A HOUSING HAVING AN ANNULAR HOUSING PART HAVING AN AXIS, AN INNER ANNULAR FACE SURROUNDING AN INTERIOR CACITY, AND AT LEAST ONE ANNULAR END FACE EXTENDING TRANSVERSELY TO THE AXIS OF SAID HOUSING PART; ROTOR MEANS ARRANGED AT LEAST PARTLY IN SAID INTERIOR CAVITY FOR TURNING MOVEMENT ABOUT A ROTOR AXIS PARALLEL TO SAID AXIS, SAID ROTOR MEANS INCLUDING MEANS FOR PARTITIONING SAID INTERIOR CAVITY INTO A PLURALITY OF FLUID RECEIVING WORKING CHAMBERS, AND A LEAST ONE COVER MEANS HAVING A PORTION EXTENDING OUTWARDLY BEYOND SAID INNER ANNULAR FACE OF SAID HOUSING PART AND DEFINING AN OPEN SPACE WITH AT LEAST PART OF SAID ANNULAR END FACE; AT LEST ONE SEALING RING LOCATED IN A PAR OF SAID SPACE AND HAVING ON ONE SIDE A SEALING FACE SUBSTANTIALLY PARALLEL TO SAID ANNULAR END FACE AND BEING IN SEALING ENGAGEMENT THEREWITH AND HAVING ON THE OTHER 